Composition for impregnating balloon fabrics



Patented on. e, 1929 ITED STATES. PATENT OFFICE EBIOH TRENCKMANN AND BRUNO TRENCKMANN, OF BERLIN-TEMPELHOF, GERMANY, I -.A.SSIGNORS,' BY MESNE ASSIGNMENTS, T0. LUFTSCHIFFBAU ZEPPELIN, GESELL- SCHAFT MIT IBESCHRANKTER HAFT'UNQ, OF FRIEDRICHSHAFEN, BODENSEE,

MANY

COMPQ SITION IOR IMPREGNATING BALLOON FABRICS 7 110 Drawing. Application filed August 27, 1921, Serial No.- 495,935, and in Germany March 3, 1916.

(GRANTEIl) Ulil'DER THE PROVISIONS THE ACT OF MARCH 3, 1921, 41 STAT. I, -1313) Our invention refers to the manufacture of balloon envelope material and more especially to an adhesive and impregnating mass for use in such manufacture. Its particular object is to produce, by aid of the said mass, a balloon envelope material of lighter weight and at the same time to obtain a saving in material as compared with the methods of manufacture carried on until now.

The material used up to date in the manufacture of balloon envelopes consisted either of waterproofed cloth or of goldbeaters skin or the like. Rubberized material involved the drawback of being'too heavy in weight. On the other hand animal products such as goldbeaters skin weretoo sensitive against friction, too little resistive to ripping and (unless a considerable number of layers were used) not sufficiently gastightl .For all these reasons animal products such as skins and intestines had to be employed in a number of superposed layers, this way of proceeding however leading to an enormous consumption of material so that it proved impossible to satisfy the demand.

All these drawbacks are obviated in a very simple and yet effective manner by using the mass forming the object of the present invention, such mass substantially consisting of a mixture of glue, preferably bone-glue, or some other material having the principal characteristics of glue, and .a substance or substances adapted to render the glue as well as the fabric, skin or other material, to which it is applied, elastic and gastight, amongst such substances being oils, such as Turkey red oil or other oils having similar properties glycerin and the like. Of substances adapted toreplace ordinary or bone-glue we merely mention as the most conspicuous isinglass, casein and gelatine.

The preferred mixture consists of 100 parts water, 10 parts gelatine, 10 parts Turkey red oil or turcon oil, this-being a substitute for the. former, and 5 parts glycerine, 0,25 parts bichromate of potash or formaldehyde .being present, if desired, in order to render the mixture highly waterproof.

'Byaid of this mixture a balloon envelope material is obtained which is superior to all existing materials, either of vegetable or animal origin inasmuch as it presents the ador other textile material and, if used in this Way, renders the fabric absolutely gasand watertight, without unduly increaslng its weight, its elasticity being so great as to enable it to withstand all stresses acting on the envelope. I

The mass having a. composition as described above is then preferably spread on the stretched fabric in such manner that the spreading machine is at firstadjusted for applying only a very thin coating to the fabric, the subsequent coatings from the third or fourth upwards being made thicker. In'- stead of spreading the impregnating mass on the fabric, 'we may dip the fabric into the mass, the fabric being thereafter freed from the impregnating mass in excess by causing it to pass between a pair of cylinders: In this case as well, we prefer starting with a slight impregnation. In'order to render the product thus obtained waterproof, its inner and outer surfaces preferably receive a coating of good balloon varnish. v

(The foregoing was disclosed in applicants co-pending application Ser; No. 495,934. It was required by the Patent Oflice to be divided out of that application by oflice action of January 18, 1924. Applicants have inserted this matter in this instant application rather than filing a division ap-- plication and thus avoiding a multiplicity of applications which has been condemned by the courts-see Norden v. Spaulding C. D.

1905 p. 588. Moreover this'subject matter is specifically disclosed in German Patent No. 307,755 which is supplementary or addi-' tional to German Patent No. 303,809.)

It will be understood that without departspecific use of glycerine or Turkey red oil as set forth in the specification. Oils, non-soluble fatty acids and the like can be employed in lieu thereof. The essence of the invention resides in a mixture of animal glue and a substance, or substances, adapted to render the glue elastic, a list of such substances having been hereinbefore set forth.

We claim:

A composition for impregnating'balloon fabrics adapted to be applied to cotton fabrics and the like, and when so applied and dried,

to render such fabrics gas-tight without unduly increasing the weight thereof, and without substantially reducing their'flexibility or elasticity, such composition comprising a glue-like substance, Turkey red oilapprommately equal in quantity to the glue-like substance, approximately ten times as much water as the glue-like substance and approximately half as much glycerine as the glue-like substance.

In testimony whereof we hereunto aflix our signatures.

ERICH TRENCKMANN. BRUNO TRENCKMANN. 

